Improvement of gas exchange by apneic oxygenation with nasal prong during fiberoptic intubation in fully relaxed patients

To evaluate the effect of apneic oxygenation with a nasal prong during fiberoptic orotracheal intubation (FOI) in fully relaxed patients, 46 patients, who underwent tympanomastoidectomy under general anesthesia whose intubation lasted more than 3 but less than 4 minutes, were studied. Changes of arterial oxygen tension (PaO₂), arterial carbon dioxide tension (PaCO₂) and vital signs were measured every minute. Twenty-three patients who underwent FOI in apneic state without oxygen administration (Group I), showed similar increases in heart rate (HR) and mean arterial pressure (MAP) to the other 23 patients who received 5 L/min of apneic oxygenation (Group II) with nasal prong. PaCO₂ increased less and PaO₂ decreased less in Group II at 3 minutes. In summary, apneic oxygenation during fiberoptic orotracheal intubation in fully relaxed patients is useful because it could delay the onset of hypoxia and hypercarbia, thereby providing extra time for intubation. And attempts to intubate a fully relaxed patient could probably be kept at least under 3 minutes.